Electromagnet.



E. SCHWARTZ.

ELECTROMAGNET.

APPLmATmN rlLEDAuGl, 191s.

1,997,919. 1116111611 Mar. 19,1919.

fan/Hna 5c Hwa/f r z UNTTED sTATEs PATENT OFFICE.

EDWARD SCH-WARTZ, 0F NEW YORK, N. Y., AS'SIFGNOR TO MANHATTAN ELECTRICAL' SUPPLY COMPANY, 0F JERSEY CITY, NEW JERSEY, A. COREORATION 0F MASSA- CH'USETTS.

ELECTROMAGNET.

Specification of Letters Patent.

Application led August 31, 1918. Serial No. 252,162.

To all whom z't may concern;

Be it known that I, EDWARD SCHWARTZ, a citizen of the United States of America, residing in the city, county, and State of'. New York, have invented a certain new-and useful Improvement in an Electromagnet, of which lthe following is a speciication.=

My invention rela-tes to electromagnets and particularly to electric buzzers, the object of my invention being to provide eliicient, reliable, and readily adjustable buzzers of improved construction.

In the accompanying drawings,

Figure 1 is a plan of the buzzer in which my invention is illustratively embodied;

Fig. 2 is a front elevation thereof;

Fig. 3 is a section on the line 3--3 of Fig. 2; and

Fig. 4 is an elevation of the armature' alone.

As here shown the buzzer is mounted on an insulating base 10 to which itis secured by a pair of screws 11 and 12 taking into the base of the frame. The latter is preferably stamped from sheet iron and bent to a general U-shape, the upright 14 rising at right angles `from the rear margin of the base. A pair of arms 15 and 16 form the top of the frame parallel to the base and constitute integral extensions at opposite ends of the upright 14. These arms are united at the front of the frame by a panel 17 offset upward at right angles thereto and having a central top flange 18 and a central down-v wardly projecting j boss 19.- A boss 20,.

alined with the latter, rises from the top of the upright 14. Core pins 21 and 22 pierce the upright 14 and support the electromagnet coils 23 and 24 on axes parallel with the base. A resist-ance coil 25 to choke arcing at the armature contact, is supported at the top of the frame by a screw bolt 26 taking into the top flange 18 and is suitably connected "between the magnet coils and the frame.

The armature 27 is strucky from spring sheet metal and depends from Jthe top flange 18 of the frame, to the front of which it is secured by a pair of clamping screws 28 and 29 which pass through the clamp plate 30, and a pair of vslots 31' in the head 32 of the armature, so that the latter may be vertically adjusted. In order to increase the flexibility of the vibratory portion of the armature and to maintain its spring action uniform in various positions of adjustment, its body is apertured at 33 to form a pair of spring arms v34 and 35 which connect the armature bar proper 36 with the head 32 thereof.

Into this aperture 33, a tongue 37 projectsl from the head 32, and in adjusted position alines with the bosses 19 and 20. This tongue forms an abutment against which the adjusting pin 38 bears. In the form here shown this pin has a threaded area 39 adjacent its knurled head 40 and works in a tapped hole in boss 20, While the stem of the pin passes freely through the guide pole in boss 19 into engagement with the tongue 37. Riveted at 41 on the armature bar 36 is a bridge strap 42 carrying a platinum contact 43.

The coperating contact 44 of the buzzer is also preferably of platinum in the form of a button at the end of screw 45. The latter is mounted in split standard 46, the offset base of which is secured by screws 47 to a foot piece extension 48 of the frame base, but insulated therefrom by strips 49 of mica or the like.

The lead Wires 50 and 51 are connected by the binding screws 52 and 53 respectively,- one, viz., 50, carried by terminal plate- 54, and the other, viz., 53, carried by an arm 55 extending t0 one side of the split standard 46. The terminal plate 54 is insulated from the frame of the buzzer and a lead 56 from one of the magnet coils is secured thereto at 57, in any suitable Way, as for instance, by soldering. A third binding screw 58 is mounted in the lug 59 at one side of the upright 14 and affords an extension connection, if desired.

The arrangement indicated is particularly advantageous by reason of the fact that the pull of the magnets upon the armature bar is equalized under all conditions due to the oscillation of the armature on an axis at right angles to the axes of the magnet-,coils and its location on a plane parallel to the plane of said. axes instead of alined therewith,-as is the common construction. The spacing of the armature bar from the magnet cores by the adjusting pin 38 does not affect the flexibility of the spring arms 34 and 35, the spring action of which is uniform under all conditions owin to their sepa-ration from the tongue 37 against which the adjusting pin bears. The mounting of the choke co1l 25 above the armature frame removes a disturbing influence from the field Patented Har. 18, 1919.

ot the elcctromagnct coils 23 and 2t and iurthermore presents the manufacturing advantage oi' being an independent element which may be wound separately without interfering with the winding of either of the magnet coils. lts connection in the buzzer circuit is readily edected during assembly of the coils on the frame. The construction as a whole is simple and economical, the part-s are not easily disarranged and the a1'- mature is susceptible of very delicate adjustment due to the fact that the pin 38 and screw pin e5 bear against its opposite sides.

Variations in detail of construction will' readily occui` to those skilled in the art, without departing from what l claim as my inyention.

ll claim l. An electromagnetic buzzer comprising a frame having a base, a` standard rising from the rear margin thereof and a top extending forwardly from said standard and parallel to the base to term a substantially lil-shaped frame, a pair ot electromagnets mounted on the standard within the :frame and with their axes lying in a plane sub-- stantially parallel to the base, a spring armature depending from the top ot the trame in iront of the magnet cores, an adjusting screw supported by the standard and bearing against the rear of the arma- Jiure to regulate the spacing thereot` from the magnets, and an adjustable fixed contact normally engaging the :liront oit said armature to complete the buzzer circuit therethrough.

2. ln combination with a construction such as specilied in claim l, a choke coil mounted on the iframe above the top thereof and connected in the circuit of the mag net coils.

3. An electromagnetic buzzer comprising a :trame having a. base, a standard rising from the rear margin thereof and a top extending orwardly from said standard and parallel to the base to form a substantially lll-shaped ira-me, a pair of electromagnets mounted on the standard within the frame and with their axes lying in a plane substantially parallel to the base, a flange rising from the front edge oi the frame top, a spring armature having its head rigidly secured to said harige and depending thereirom to a point in front ci the armature cores, an adjusting screw supported by the naeaere standard and bearing against the rear of the armature to regulate the spacing thereof from the magnets, and an adjustable hired contact normally engaging the front of said armature to complete the buzzer circuit therethrough.

4. ln a construction such as speciiied in claim 3, a. choke coil mounted on said harige and overlying the magnet coils but above the top of the frame and connected in the circuit of the magnet coils.

5. ln an electromagnetic buzzer, a frame having a base, a standard rising from the rear margin thereof, a top extending orwardly from said standard and parallel 4to the base to form a substantially U-shaped trame, an armature depending from the Eront of said top, an adjusting screw for the armature carried by the standard and a depending boss at the front of the trame pierced to ail'ord a supporting guide for the forward end of the adjusting screw adjacent the armature.

6. ln an electromagnetic buzzer, a spring metal armature having a supporting head, and a bar spaced therefrom and integral spring arms connecting said'head and bar.

'l'. ln an electromagnetic buzzer, a trame having a base, a standard rising from the rear margin thereof, a top extending torwardly from said standard and parallel to the base to form a substantially lll-shaped frame, an armature depending from the `iront of said top, an adjusting screw carried by the standard and a depending boss at the front of the frame pierced to aiiord a supporting guide for the forward end of the adjusting screw adjacent the armature, together with a toot piece extension at the forward end-edge of the base, a terminal standard secured to but insulated from said :toot piece and a screw contact mounted in said standard and coperating with the armature, substantially as described.

8. ln an electromagnetic buzzer, a spring metal arma-ture having a supporting head and a bar spaced therefrom and integral spring arms connecting said head and bar, together with a tongue projecting from the head area into the space between the arms to aord a bearing abutment for an adjusting screw.

ln testimony whereof l'haye signed my name to this speciiication.

SCHWARTZ. 

